1. Field of the Invention
The present invention relates generally to a display method, a film and a display device using magnetic particles, and specifically to a display method, a film and a display device using magnetic particles by: applying a first magnetic field to particles having a magnetic property dispersed in a solvent so that particles are aligned in a direction parallel to a direction of the first magnetic field, and thus particle chains are formed; applying a second magnetic field to the formed particle chains so that the particle chains move in a direction close to a display surface; and changing a strength or a direction of the second magnetic field or applying a third magnetic field in an opposite direction of the second magnetic field so that the particle chains move away from the display surface, and thus the intensity and the color of the information displayed through the display surface is adjusted.
2. Description of the Prior Art
A magnetic board using magnetic powder or a magnetic field is widely used as a writing tool for child since it has no color or no waste. As an example of the conventional art, it has been disclosed that magnetic particles are dispersed in a colored fluid and are filled in a structural body having barriers, and then a magnetic field is partially applied using a magnetic pen on the top of the structural body so that the magnetic particles move to display certain information, or a magnetic field in an opposite direction is applied using a magnetic plate movable in a lower portion of the structural body so that the information displayed by the magnetic particles are entirely erased.
FIG. 1 is a diagram illustrating an example of a device for displaying according to the conventional art. With reference to FIG. 1, the color of particles 110 may be displayed by applying a magnetic field with a magnet 130 positioned on the top of the device for displaying and moving the particles 110 in a solvent 120 to the upper portion (that is, in case of writing), and the color of particles 110 may not be displayed by entirely applying a magnetic field in an opposite direction with a magnet 140 positioned on the lower portion of the device for displaying and movable from side to side and moving the particles 110 in a solvent 120 to the lower portion (that is, in case of erasing).
However, according to the conventional art, it is difficult to partially erase displayed information, adjust intensity or color of the displayed information, and manufacture the device for displaying to be thin and flexible.
Accordingly, the inventors of the present invention have developed a display method, a film, and a display device using magnetic particles by applying a first magnetic field to magnetic particles dispersed in a solvent so that the particles are aligned in a direction parallel to a direction of the first magnetic field to form particle chains, applying a second magnetic field to the formed particle chains so that the particle chains move in a direction close to the display surface, and changing an intensity or direction of the second magnetic field or applying a third magnetic field in an opposite direction to the second magnetic field so that the particle chains move away from the display surface to display the color of the particles through the display surface, and the inventors have conceived various modifications using the same.